Police use several restraint types - standard metal cuffs (chain, hinged, rigid) and disposable nylon flex-cuffs - chosen based on control needs and safety. Training, double-locking, monitoring circulation, and departmental policies reduce risks such as restraint-related injury and positional asphyxia. Agencies may also use leg restraints or transport devices when appropriate.
Overview
Police use several types of handcuffs and restraints to secure people during arrests and transport. The goals are safety for officers, the person being detained, and the public; control of movement; and prevention of escape. Training and department policies guide which restraint is appropriate in a given situation.
Steel handcuffs: the standard
Traditional metal handcuffs remain the most common. They typically have a ratchet locking mechanism and a double-lock feature that prevents the cuffs from tightening further once set. Common configurations include a short chain between the two wrist rings, a hinged connection, or a rigid bar. Officers are trained to apply them firmly but not so tight as to cut off circulation.
Many metal cuffs use a small removable key that opens the lock. Officers also learn to check fit (a finger should slide between cuff and wrist) and to monitor for numbness or swelling after application.
Disposable restraints (flex-cuffs)
Nylon or plastic "flex-cuffs" are single-use restraints widely used for mass arrests, crowd-control situations, or when officers need many restraints on hand. They are lightweight, inexpensive, and cut off with scissors or a cutting tool once the person reaches a processing area.
Hinged and rigid designs
Hinged and rigid models restrict wrist rotation more than chain-linked cuffs and offer greater control during transport or when a subject resists. They can reduce an officer's need to use additional force, but officers must still monitor for discomfort and circulation issues.
Alternatives and supplements
Departments also use leg restraints, hobble straps, and transport belts in specific situations. Medical or behavioral concerns may require different approaches, such as loosening restraints or seeking medical evaluation.
Safety, training, and policy
Modern practice emphasizes training: proper application, use of the double-lock, recognition of circulation problems, and minimizing time in restraints. Agencies increasingly pair restraint policies with medical and use-of-force protocols and - as equipment allows - record restraint events with body-worn cameras.
Restraint-related injuries and positional asphyxia are recognized risks. Officers are trained to avoid prolonged prone restraint and to seek medical attention if the detained person reports trouble breathing, chest pain, or shows signs of distress.
Summary
Handcuffs and restraints vary by design and purpose: metal chain, hinged, and rigid cuffs for general policing, and disposable flex-cuffs for temporary mass restraint. Proper training, monitoring, and departmental policy determine which option to use and help reduce risk to everyone involved. : confirm whether a single universal key still opens most metal handcuff models used across U.S. agencies (as of 2025).
- Confirm whether a single universal handcuff key still opens most metal handcuff models used across U.S. law enforcement agencies as of 2025.